We see two parallel lines crossed by a transversal.
The two labelled angles are alternate interior angles, hence they are equal.
The equality allows us to equate the two expressions and hence solve for x.
8x-3=5x+42
transpose terms
8x-5x=42+3
solve for x
3x=45
so x=45/3=15.
This means 5x+42=5*15+42=75+42=117 degrees.
Answer:
Any real number.
Step-by-step explanation:
I dunno what you're asking, but Im assuming you need what a equals to.

The answer is any real number.
Answer:
Step-by-step explanation:
B + 87 +78 +66 = 360
B = 129 °
the angle next to B then is
180 = 129 + b '
51 ° = b '
A + 61 + b ' = 180
A = 68 °
Step-by-step explanation:
